1. Field of the Invention
The present invention relates to an image processing apparatus, an image pickup apparatus, an image processing method, and a program.
2. Description of the Related Art
There is known a method for restoring an image based on an optical transfer function (“OTF”) or a point spread function (“PSF”) of an image pickup system (Japanese Patent Laid-Open No. (“JP”) 2008-211679). Other prior art include JPs. 2008-85773 and 10-319518.
The conventional image restoration may cause a false color due to a chromatic aberration. For instance, assume a first object and a second object in a screen where among lights of the RGB wavelength regions, the G light is focused on and the R light is defocused from the first object due to the chromatic aberration, and the R light is focused on and the G light is defocused from the second object due to the chromatic aberration.
According to the conventional image restoration, the OTF of an image pickup state of the first object for each of the RGB lights is utilized for the image restorations of both the first object and the second object. As a result, an image of the first object is properly restored whereas a restored image of the second object may be greenish (or a false color may be generated). This is because although a relationship in which the G light is focused and the R light is defocused from the first object is inverted in the second object, the OTF that reflects the pre-inversion relationship is used for the second object.